Pillars of the Plane: An Overview of The OV-10 Build

Of all the planes that flew our skies, the OV-10 Bronco might be one of the most iconic warbirds out there. In the previous blog posts, the OV-10 was discussed as a warplane that came out of necessity by the three branches of the military, namely the army, the navy, and the air force, as well as the efforts of 16 companies that competed to get their design accepted by the military. It was depicted as a figure in the skies that swept down on Victor Charlies in the Ho Chi Minh trail during the Vietnam War, providing air support for the friendlies and offensive strikes to anyone who took up arms for the communist ideology. These blogs have mentioned the warplane in all its glory, and rightfully so. The OV-10 is indeed one that will definitely go down in history. But with all these insights of the plane’s contributions in various theaters of war, one thing remains in the minds of enthusiasts and amateurs alike – the restoration of these metallic birds of prey. Exactly why, even after years of service, is the OV-Bronco being restored? What’s with the OV-10 that pushes people to say “we need to build it to complete working order”?

This blog post focuses on the 3 main build components that make up the OV-10 Bronco, mainly the frame, the engine, and the cockpit. Now, we’re not saying these three are considered the only important components, but it’s these features that define the Bronco for what it is— a warplane different from the rest. These features make the OV-10 Bronco a plane that stands at the helm of history as one of the best warplanes in terms of endurance and maneuverability.

First up is the frame. When we talk about aviation, the design of the plane itself can have a tremendous impact on how the plane performs. The dimensions, the contours, the wingspan, the design of the tail, all of which contribute to how well a plane handles itself during flight.

The design of the OV-10 Bronco did not allow for maximum aerodynamicity. However, the double-boom design and the high-lift wing design optimized maneuverability. The double-booms are connected by a tail-plane, which at first glance looks strange to the untrained observer. However, this tail-plane keeps the plane stable during missions where maneuverability and delicate control was needed over speed. The wings also maximized lift and low-speed handling. While some old-fashioned pilots complained of speeds below 350 knots, these planes were relatively slow yet agile enough to escort helicopters and other planes at that time. The combination of these factors: the double booms, the tailplane, and the high-lift wings, give the OV-10 its unique maneuverability and agility.

Here at OV-10 Squadron, our team focuses on restoring the overall design. As with all restorations, the outer portion should remain true to the original. We painstakingly fabricate any missing frame pieces during the build. If there are holes on the frame, we repair it using the same material used on the rest of the frame and treat it so it blends well with the rest. A doubler is placed beneath the patch, and a cover piece, usually the next size thicker, is placed on top of the patch as well. These pieces are then riveted together to ensure that the repair is as sturdy as possible. We see to it that the restoration of the frame is accurate in order for the plane to be as authentic as possible.

The engine of the plane is one of the components that make the Bronco stand out from the competition. The Bronco was generally lauded for its incredible endurance back during the days of the Vietnam War. Captain James Richmond of the 23rd Tactical Air Support Squadron in Nakhon Phanom RTAFB (Royal Thai Air Force Base), Thailand, commented that the Bronco could handle five and three-quarters of flying, even though most missions required only five and a half hours of flight. As it landed after each mission, service crews would note that it still had fuel left for more. Later models of the OV-10 would boast a Cockpit Management System, which fed pilot and observer with information on navigation, countermeasures, and weapon systems through a Cathode Ray Tube or CRT display and an alphanumeric keyboard. In fact, its visibility and heavy ordnance capacity made older OV-10A models firefighting lead planes for the California Department of Forestry.

Aside from its endurance, the OV-10 was lauded for its ability to land and take off in as little time as possible. This was partially due to the fact that the OV-10 was made for recon and light attack in a heavily waterlogged, forested area. The longer a plane stayed on the ground, the more it would struggle with the difficult terrain. The OV-10 Bronco only required 10 seconds for its plane and landing gear to deploy, and only required minimal taxiing before it took off. The landing gear not only allowed for 20 feet of sinking but also carried enough power to take off even in the muddiest of conditions. Our team wishes to bring that kind of performance back with our restorations of various OV-10 Broncos.

The Honeywell TPE331 engine, originally designed by Garrett AiResearch, is the power plant that gives the OV-10 its distinct performance. We at OV-10 Squadron aim to have these monsters working. It’s not like any car where one could simply mount a compatible engine for it to work. If we did that on our OV-10s, we are not only compromising the originality of the plane but are also taking away the OV-10s characteristics. That is why we maintain the integrity of the engines and send it to the folks at CTEC. Copperstate Turbine Engine Company is comprised of dedicated employees who have worked with Garrett AiResearch at one point in time. When it comes to dealing with these engines, they know what they’re doing.

The cockpit is also one of the OV-10 Bronco’s most striking qualities. The general shape of the Bronco includes a large, bulbous canopy and a short nose to maximize visibility. In reconnaissance missions, visibility is a must, and the greenhouse canopy of the OV-10 allowed for as much of that during the 70s. The twin-boom design also avoided the problem of the back of the plane blocking the rear view. This plane was one of the first to allow for 360-degree visibility, especially in front and below. This was useful in reconnaissance missions done with the naked eye, of which there were many. These missions had planes fly as low as 1500 feet. However, some recon flights required heights above 6,500 feet, necessitating the use of binoculars. This glass “greenhouse” got warm rather easily, so the side panels were swung open to allow cool air to circulate, usually while the plane was taxiing or awaiting command.

Behind the cockpit is a spacious compartment, large enough to carry armaments or people. Paratroopers can be escorted for drop missions. As a medical support aircraft, these agile flight units can carry up to four walking wounded and bring them to safety. Our team aims to replicate this spacious compartment along with the rest of the unique nuts and bolts of the OV-10 Bronco, staying true to history and the proud tradition of the US Air Force.

All of these unique qualities associated with the three components of the OV-10 Bronco make it worthy to bring this powerful plane back into place, piece by piece. We aim to replicate the maneuverability of this plane by utilizing the very same parts that sent it airborne. Knowing the components, and more importantly, what makes a plane unique, is vital in reconstructing such a complex yet awesome machine.

We have a team of committed people who want to bring this bird back to its former glory. We at OV-10 Squadron aim not only to accurately replicate the look of this warbird of old but also make it operational. Think of it this way, a Harley Davidson motorcycle is known for its distinctive sound. Take that away and it’s just another vehicle. The same concept goes with the OV-10 Bronco, modify any of the three components and the plane simply loses its unique characteristics. That is why we see to it that these components are true to the original design, to keep the Bronco on a league of its own.

If you want to be part of the restoration process of the OV-10 Bronco, come and visit our headquarters at the Leading Edge Avionics Hangar at John Wayne/Orange County Airport, 19300 Ike Jones Road, Santa Ana, CA 92707. The restoration hangar is located at Chino Airport, California. You can also leave us a message on our website and we’ll get back to you as soon as we can.

2 Comments

John Ballard
on August 6, 2018 at 2:46 pm

You have probably heard it already, but the engines were Garrett T76’s NOT Honeywell TPE331 engine. The TPE331’s are the commercial engines and are inverted in mount of the T76’s (the TPE331 were talked about but not put on the Bronco). All the problems identified in the T76 program were used to improve the 331’s, many corrections were offered back to the military as engine changes but at a cost.